We fabricate the Tm-doped double cladding silica fiber by using the vapor-solution hybrid-doping method, then build up an all-fiber Tin-doped fiber laser which can provide the output power of up to 121 W, correspondin...We fabricate the Tm-doped double cladding silica fiber by using the vapor-solution hybrid-doping method, then build up an all-fiber Tin-doped fiber laser which can provide the output power of up to 121 W, corresponding to a slope efficiency of 51% and an optical-optical efficiency of 48%. By using the domestic Tin-doped fiber, it is the first time a hundred-watt level output at 1915nm has been achieved, to the best of our knowledge. The thermal effect of Tm-doped fiber laser is also analyzed.展开更多
An actively mode-locked Ho： YAG laser pumped by a diode-pumped Tin-doped fiber laser is reported. For the cw operation, we obtain the maximum output power of 3.43 W with a central wavelength 2022.2nm at the maximum i...An actively mode-locked Ho： YAG laser pumped by a diode-pumped Tin-doped fiber laser is reported. For the cw operation, we obtain the maximum output power of 3.43 W with a central wavelength 2022.2nm at the maximum incident pump power of 11.4 W, corresponding to a slope efficiency of 34.5%. The beam quality factor M2 is 1.16, and the output beam is close to fundamental TEMoo. In the case of the CWML operation, a stable pulse train is generated with an average output power up to 3.41 W with a slope efficiency of 34.3% at the incident pump power of 11.4 W and a pulse duration of 294ps at a repetition rate of 81.92MHz. In addition, the maximum single pulse energy is 41.6nJ.展开更多
We propose and demonstrate a synchronously pumped mode-locked Tm-doped fiber（TDF） laser without any extra mode-locking elements. Pumped by a 1.56 μm pulse fiber laser, the TDF laser generates 1.17 ps pulses with a ...We propose and demonstrate a synchronously pumped mode-locked Tm-doped fiber（TDF） laser without any extra mode-locking elements. Pumped by a 1.56 μm pulse fiber laser, the TDF laser generates 1.17 ps pulses with a spectral width of 9.7 nm and a repetition rate of 9.33 MHz. The emission wavelength is tunable along with the cavity length detuning in a wide range of 3 mm. The high detuning toleration is beneficial to achieve high temperature and vibration stability in all-fiber configuration lasers.展开更多
GeSe has recently emerged as a photovoltaic absorber material due to its attractive optical and electrical properties as well as earth abundancy and low toxicity.However,the efficiency of GeSe thin-film solar cells(TF...GeSe has recently emerged as a photovoltaic absorber material due to its attractive optical and electrical properties as well as earth abundancy and low toxicity.However,the efficiency of GeSe thin-film solar cells(TFSCs)is still low compared to the Shockley–Queisser limit.Point defects are believed to play important roles in the electrical and optical properties of GeSe thin films.Here,we perform first-principles calculations to study the defect characteristics of GeSe.Our results demonstrate that no matter under the Ge-rich or Se-rich condition,the Fermi level is always located near the valence band edge,leading to the p-type conductivity of undoped samples.Under Se-rich condition,the Ge vacancy(V_(Ge))has the lowest formation energy,with a(0/2–)charge-state transition level at 0.22 eV above the valence band edge.The high density(above 10^(17)cm^(-3))and shallow level of VGeimply that it is the p-type origin of GeSe.Under Se-rich growth condition,Seihas a low formation energy in the neutral state,but it does not introduce any defect level in the band gap,suggesting that it neither contributes to electrical conductivity nor induces non-radiative recombination.In addition,Gei introduces a deep charge-state transition level,making it a possible recombination center.Therefore,we propose that the Se-rich condition should be adopted to fabricate high-efficiency GeSe solar cells.展开更多
Selector devices are indispensable components of large-scale memristor array systems.The thereinto,ovonic threshold switching(OTS)selector is one of the most suitable candidates for selector devices,owing to its high ...Selector devices are indispensable components of large-scale memristor array systems.The thereinto,ovonic threshold switching(OTS)selector is one of the most suitable candidates for selector devices,owing to its high selectivity and scalability.However,OTS selectors suffer from poor endurance and stability which are persistent tricky problems for applica-tion.Here,we report on a multilayer OTS selector based on simple GeSe and doped-GeSe.The experimental results show im-proving selector performed extraordinary endurance up to 1010 and the fluctuation of threshold voltage is 2.5%.The reason for the improvement may lie in more interface states which strengthen the interaction among individual layers.These develop-ments pave the way towards tuning a new class of OTS materials engineering,ensuring improvement of electrical perform-ance.展开更多
GeSe nanosheets were prepared by ultrasonic-assisted liquid<span><span><span style="font-family:;" "=""> </span></span></span><span><span><sp...GeSe nanosheets were prepared by ultrasonic-assisted liquid<span><span><span style="font-family:;" "=""> </span></span></span><span><span><span><span style="font-family:Verdana;">phase exfoliation (LPE), and the nonlinear saturated absorption performance was experimentally studied. The modulation depth and saturation intensity of the prepared GeSe saturable absorber (SA) were 15% and 1.44 MW/cm</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;">, respectively. Us</span><span style="font-family:Verdana;">ing the saturated absorption characteristics of GeSe SA, a passively Q-switched </span><span style="font-family:Verdana;">erbium-doped fiber laser was systematically demonstrated. As the pump</span><span style="font-family:Verdana;"> power increases, the pulse repetition frequency increases from 22.8 kHz to 77.59 </span><span style="font-family:Verdana;">kHz. The shortest pulse duration is 1.51 μs, and the corresponding pulse</span><span style="font-family:Verdana;"> energy is 46.14 nJ. Experimental results show that GeSe nanosheets can be used as high-efficiency SA in fiber lasers. Our results will provide a useful reference for demonstrating pulsed fiber lasers based on GeSe equipment.</span></span></span></span>展开更多
基金Supported by the National High-Technology Research and Development Program of China under Grant No 2013AA031501the National Natural Science Foundation of China for Director Fund of WNLO
文摘We fabricate the Tm-doped double cladding silica fiber by using the vapor-solution hybrid-doping method, then build up an all-fiber Tin-doped fiber laser which can provide the output power of up to 121 W, corresponding to a slope efficiency of 51% and an optical-optical efficiency of 48%. By using the domestic Tin-doped fiber, it is the first time a hundred-watt level output at 1915nm has been achieved, to the best of our knowledge. The thermal effect of Tm-doped fiber laser is also analyzed.
基金Supported by the National Natural Science Foundation of China under Grant Nos 61308009 and 61405047the China Postdoctoral Science Foundation Funded Project under Grant Nos 2013M540288 and 2015M570290+2 种基金the Fundamental Research Funds for the Central Universities Grant under Grant Nos HIT.NSRIF.2014044 and HIT.NSRIF.2015042the Science Fund for Outstanding Youths of Heilongjiang Province under Grant No JQ201310the Heilongjiang Postdoctoral Science Foundation Funded Project under Grant No LBH-Z14085
文摘An actively mode-locked Ho： YAG laser pumped by a diode-pumped Tin-doped fiber laser is reported. For the cw operation, we obtain the maximum output power of 3.43 W with a central wavelength 2022.2nm at the maximum incident pump power of 11.4 W, corresponding to a slope efficiency of 34.5%. The beam quality factor M2 is 1.16, and the output beam is close to fundamental TEMoo. In the case of the CWML operation, a stable pulse train is generated with an average output power up to 3.41 W with a slope efficiency of 34.3% at the incident pump power of 11.4 W and a pulse duration of 294ps at a repetition rate of 81.92MHz. In addition, the maximum single pulse energy is 41.6nJ.
基金Supported by the National Natural Science Foundation of China under Grant Nos 61675188 and 61875052the Open Fund of Key Laboratory Pulse Power Laser Technology of China under Grant No SKL2016KF03
文摘We propose and demonstrate a synchronously pumped mode-locked Tm-doped fiber（TDF） laser without any extra mode-locking elements. Pumped by a 1.56 μm pulse fiber laser, the TDF laser generates 1.17 ps pulses with a spectral width of 9.7 nm and a repetition rate of 9.33 MHz. The emission wavelength is tunable along with the cavity length detuning in a wide range of 3 mm. The high detuning toleration is beneficial to achieve high temperature and vibration stability in all-fiber configuration lasers.
基金supported by Shanghai Academic/Technology Research Leader(Grant No.19XD1421300)the National Natural Science Foundation of China(Grant No.12174060)+3 种基金Program for Professor of Special Appointment(Eastern Scholar TP2019019)the National Key Research and Development Program of China(Grant No.2019YFE0118100)State Key Laboratory of ASIC&System(Grant No.2021MS006)Young Scientist Project of MOE Innovation Platform。
文摘GeSe has recently emerged as a photovoltaic absorber material due to its attractive optical and electrical properties as well as earth abundancy and low toxicity.However,the efficiency of GeSe thin-film solar cells(TFSCs)is still low compared to the Shockley–Queisser limit.Point defects are believed to play important roles in the electrical and optical properties of GeSe thin films.Here,we perform first-principles calculations to study the defect characteristics of GeSe.Our results demonstrate that no matter under the Ge-rich or Se-rich condition,the Fermi level is always located near the valence band edge,leading to the p-type conductivity of undoped samples.Under Se-rich condition,the Ge vacancy(V_(Ge))has the lowest formation energy,with a(0/2–)charge-state transition level at 0.22 eV above the valence band edge.The high density(above 10^(17)cm^(-3))and shallow level of VGeimply that it is the p-type origin of GeSe.Under Se-rich growth condition,Seihas a low formation energy in the neutral state,but it does not introduce any defect level in the band gap,suggesting that it neither contributes to electrical conductivity nor induces non-radiative recombination.In addition,Gei introduces a deep charge-state transition level,making it a possible recombination center.Therefore,we propose that the Se-rich condition should be adopted to fabricate high-efficiency GeSe solar cells.
基金supported by National Natural Science Foundation of China(Grant Nos.61974164,62074166,61804181,62004219,and 6200422).
文摘Selector devices are indispensable components of large-scale memristor array systems.The thereinto,ovonic threshold switching(OTS)selector is one of the most suitable candidates for selector devices,owing to its high selectivity and scalability.However,OTS selectors suffer from poor endurance and stability which are persistent tricky problems for applica-tion.Here,we report on a multilayer OTS selector based on simple GeSe and doped-GeSe.The experimental results show im-proving selector performed extraordinary endurance up to 1010 and the fluctuation of threshold voltage is 2.5%.The reason for the improvement may lie in more interface states which strengthen the interaction among individual layers.These develop-ments pave the way towards tuning a new class of OTS materials engineering,ensuring improvement of electrical perform-ance.
文摘GeSe nanosheets were prepared by ultrasonic-assisted liquid<span><span><span style="font-family:;" "=""> </span></span></span><span><span><span><span style="font-family:Verdana;">phase exfoliation (LPE), and the nonlinear saturated absorption performance was experimentally studied. The modulation depth and saturation intensity of the prepared GeSe saturable absorber (SA) were 15% and 1.44 MW/cm</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;">, respectively. Us</span><span style="font-family:Verdana;">ing the saturated absorption characteristics of GeSe SA, a passively Q-switched </span><span style="font-family:Verdana;">erbium-doped fiber laser was systematically demonstrated. As the pump</span><span style="font-family:Verdana;"> power increases, the pulse repetition frequency increases from 22.8 kHz to 77.59 </span><span style="font-family:Verdana;">kHz. The shortest pulse duration is 1.51 μs, and the corresponding pulse</span><span style="font-family:Verdana;"> energy is 46.14 nJ. Experimental results show that GeSe nanosheets can be used as high-efficiency SA in fiber lasers. Our results will provide a useful reference for demonstrating pulsed fiber lasers based on GeSe equipment.</span></span></span></span>
